The present invention relates to a watertight suit.
Several types of watertight suits, for example, a dry suit used for diving, a life jacket, a fisherman's long rubber pants, etc., are well known.
The dry suit mentioned above generally includes an air inlet valve for introducing air into the inside of the dry suit from an air tank to permit adjustment of inner air pressure according to diving depth, etc., and an air outlet valve for discharging the air from the inside of the dry suit. In such dry suits, the air outlet valves can discharge the air when a diver is in a horizontal position or a standing position, in which his head is located above the horizontal plane, in the water. The air outlet valve is usually disposed an upper arm part of the dry suit to facilitate operation.
Since the air outlet valve is usually located in the upper part of the dry suit, the air in the dry suit concentrates in leg parts of the dry suit when the diver's legs are located above the horizontal line in the water. The air in the leg parts concentrically lifts the diver's legs upward, so that the diver cannot change his position in the water. When the diver's legs are lifted upward, outer water pressure around the legs is reduced, and a volume of the air in the leg parts of the watertight suit is expanded. As a consequence, the buoyant force applied to the leg parts is increased as the diver moves upward in the water. In the worst case, the diver rises to the water surface in a very short time, so that accidents may result, for example, development of a caisson disease.
Conventionally, divers wear weights in an attempt to prevent the accidents caused by the greater buoyant force, but such precautions do not entirely eliminate such accidents.
If a fisherman wearing long rubber pants accidentally falls into the water, his legs are lifted in the water because the air is trapped in the leg parts of the long rubber pants. As a result, he cannot lift his face above the surface of the water, and therefore is unable to breathe.
It is therefore an object of the present invention to provide a watertight suit capable of properly discharging the air within the suit and keeping the diver's position in the water.